Question

I have the following two migrations already in my database:

When I created Prices:

class CreatePrices < ActiveRecord::Migration
  def self.up
    create_table :prices do |t|
      t.string :price_name
      t.decimal :price
      t.date :date

      t.timestamps
    end
    # add_index :prices (not added)
  end

  def self.down
    drop_table :prices
  end
end

and when I added a user_id to Prices:

class AddUserIdToPrices < ActiveRecord::Migration
  def self.up
    add_column :prices, :user_id, :integer
  end
  # add_index :user_id (not added)
end

  def self.down
    remove_column :prices, :user_id
  end
end

Is there a way from the command line to add prices and user_id to index? I looked at this question and still was confused on how to go about adding indexes and the parts where I put “not added” seem like they would be error-prone because they were earlier migrations.

My question is, what is the best way for me to add indexing to prices and user_id?

Thank you for the help!

Answer 1

I think one extra migration fits well:

class AddIndexes < ActiveRecord::Migration

  def self.up
    add_index :prices, :user_id
    add_index :prices, :price
  end

  def self.down
    remove_index :prices, :user_id
    remove_index :prices, :price
  end

end

Or you can use change syntax with newer versions of rails, look at DonamiteIsTnt comment for details:

class AddIndexes < ActiveRecord::Migration

  def change
    add_index :prices, :user_id
    add_index :prices, :price
  end

end